Hashirama: When he has nightmares, they’re awful. He’s had a difficult life, so I imagine he has some pretty rough dreams. So if they’re about his s/o, and about them getting hurt or even killed, he honestly might wake up a little teary-eyed. Even if he knows it was a dream, and even if he can look at his s/o right next to him, safe and sound and unharmed, it still really hurts him. If the commotion wakes his s/o up and they see him all disheveled and distressed, they might ask what’s wrong. He won’t say anything, will just lean in and hug them hard. His s/o will have to snuggle up with him and just let him hold them for a while before he’s able to go back to bed

Tobirama: He wakes up in a cold sweat and a rapidly beating heart. He usually ignores his dreams and nightmares (like his bro, he probably has a lot) because he just doesn’t want to dwell on them. But this one with his s/o just impacts him in a different way. He might feel silly at first, he might even be frustrated with himself that he lets it get to him. He sits up in bed and just looks at his s/o for a while, hoping it will calm his pulse and clear his head, but it’s still affecting him. He’d sooner get out of bed and walk around the house or sit in his home office and do work than wake them up. He wouldn’t have a good explanation, because explaining that he had a bad dream about them is just… maybe too sentimental for him. The dream just felt so real when it was happening, and he felt helpless watching his s/o in danger. When he gets back into bed though, he just looks at them for a really long time as he tries to fall asleep, if he’s even able to

Madara: He’ll wake up from the nightmare and just stare at the ceiling for the longest time, even though on the inside, his adrenaline is high. His mind is just trying to wrap itself around the dream. He’s probably wondering why he had such an awful dream in the first place, and why his s/o had to be in it. He’s almost angry. He figures he can’t do much but deal with it. If his s/o isn’t already awake, he’s not going to bother them and wake them up just to give him some sense of peace. He won’t do that to them. If he can just watch them for a while, look at how calm they look while they sleep, it might comfort him a little. He probably won’t get much sleep the rest of the night, but it’s fine. He’d rather stay awake than risk another nightmare

Kakashi: He already has lots of trouble sleeping, so a nightmare isn’t exactly out of the ordinary, but it definitely shakes him if it was a bad one about his s/o. He thought that sleeping with a s/o would help him sleep better, and maybe it did for a while, but this nightmare is just going to ruin it for him. At least for a few nights. When it first happens, he shoots up in bed and just doesn’t really know what to do. It was just a dream, he keeps repeating in his mind. Because he knows it’s true. Knows it’s useless to get worked up about it, but he still does. He’s lost too many people in his life to be able to shake off a scenario (one he thought was real) of losing another. He’d probably get out of bed for a glass of water, or just sit somewhere and read. But it doesn’t distract him like he hoped it would. And for a few nights after that, he acts funny. His s/o might notice how he seems hesitant to get into bed, or how he keeps tossing and turning because he can’t fall asleep

Neji: It’s not likely Neji is going to really handle this well. Neji probably can’t handle intense things like this quietly. He’d wake up in a fit because he’s just so shaken. He represses lots of his emotions and fears, so it only makes sense they would manifest in a nightmare eventually. He just didn’t imagine it would be of his s/o being in harm’s way. I’m willing to bet the context of the dream had their injury/death being his fault too. It just makes it even worse. He feels guilty, but stupid at the same time for ‘falling’ for a dream. It takes a while for him to calm down and relax back into bed. If he accidentally woke his s/o up and they ask him what’s wrong, he’s a little unfair, because he eventually just snaps at them to leave it alone because he does not want to talk about it. He might apologize later for being so harsh, he just can’t help but be severe when his dream was so distressing